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Note 2 - Investments - Schedule of Amortized Costs and Fair Values of Securities (Details) - USD ($) $ in Thousands | Sep. 30, 2024 | Jun. 30, 2024 | Dec. 31, 2023 | Sep. 30, 2023 | Jun. 30, 2023 | Dec. 31, 2022
--- | --- | --- | --- | --- | --- | ---
Amortized cost, available for sale securities | $ 252,272 |  | $ 328,695 |  |  |
Gross unrealized gains, available for sale securities | 439 |  | 939 |  |  |
Gross unrealized losses, available for sale securities | (24,512) |  | (36,701) |  |  |
Total securities available-for-sale, fair value | 228,199 |  | 292,933 |  |  |
Available-for-Sale, Allowance for Credit Loss | 0 |  | 0 |  |  |
Amortized cost, held to maturity securities | 8,500 |  | 8,500 |  |  |
Gross unrealized gains, held to maturity securities | 0 |  | 0 |  |  |
Gross unrealized losses, held to maturity securities | (517) |  | (834) |  |  |
Securities held-to-maturity, at fair value | 7,983 |  | 7,666 |  |  |
Securities available for sale, HTM, ACL | 45 | $ 45 | 45 | $ 45 | $ 31 | $ 31
Amortized cost, available for sale and held to maturity securities | 260,772 |  | 337,195 |  |  |
Gross unrealized gains, available for sale and held to maturity securities | 439 |  | 939 |  |  |
Gross unrealized losses, available for sale and held to maturity securities | (25,029) |  | (37,535) |  |  |
Total securities, fair value | 236,182 |  | 300,599 |  |  |
ACL, available for sale and held to maturity securities | 45 |  | 45 |  |  |
US Government Agencies Debt Securities [Member] |  |  |  |  |  |
Amortized cost, available for sale securities | 20,242 |  | 21,151 |  |  |
Gross unrealized gains, available for sale securities | 30 |  | 46 |  |  |
Gross unrealized losses, available for sale securities | (2,590) |  | (3,179) |  |  |
Total securities available-for-sale, fair value | 17,682 |  | 18,018 |  |  |
Available-for-Sale, Allowance for Credit Loss | 0 |  | 0 |  |  |
Corporate Debt Securities [Member] |  |  |  |  |  |
Amortized cost, available for sale securities | 16,000 |  | 13,000 |  |  |
Gross unrealized gains, available for sale securities | 140 |  | 613 |  |  |
Gross unrealized losses, available for sale securities | (736) |  | (741) |  |  |
Total securities available-for-sale, fair value | 15,404 |  | 12,872 |  |  |
Available-for-Sale, Allowance for Credit Loss | 0 |  | 0 |  |  |
Amortized cost, held to maturity securities | 8,500 |  | 8,500 |  |  |
Gross unrealized gains, held to maturity securities | 0 |  | 0 |  |  |
Gross unrealized losses, held to maturity securities | (517) |  | (834) |  |  |
Securities held-to-maturity, at fair value | 7,983 |  | 7,666 |  |  |
Securities available for sale, HTM, ACL | 45 |  | 45 |  |  |
Municipal Bonds [Member] |  |  |  |  |  |
Amortized cost, available for sale securities | 83,060 |  | 138,803 |  |  |
Gross unrealized gains, available for sale securities | 4 |  | 42 |  |  |
Gross unrealized losses, available for sale securities | (10,738) |  | (19,398) |  |  |
Total securities available-for-sale, fair value | 72,326 |  | 119,447 |  |  |
Available-for-Sale, Allowance for Credit Loss | 0 |  | 0 |  |  |
Collateralized Mortgage-Backed Securities [Member] |  |  |  |  |  |
Amortized cost, available for sale securities | 120,136 |  | 112,855 |  |  |
Gross unrealized gains, available for sale securities | 261 |  | 238 |  |  |
Gross unrealized losses, available for sale securities | (9,478) |  | (11,845) |  |  |
Total securities available-for-sale, fair value | 110,919 |  | 101,248 |  |  |
Available-for-Sale, Allowance for Credit Loss | 0 |  | 0 |  |  |
U.S. Small Business Administration Securities [Member] |  |  |  |  |  |
Amortized cost, available for sale securities | 12,834 |  | 42,886 |  |  |
Gross unrealized gains, available for sale securities | 4 |  | 0 |  |  |
Gross unrealized losses, available for sale securities | (970) |  | (1,538) |  |  |
Total securities available-for-sale, fair value | 11,868 |  | 41,348 |  |  |
Available-for-Sale, Allowance for Credit Loss | $ 0 |  | $ 0 |  |  |

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